Slack User MCP Server

MCP Server for the Slack API, enabling Claude to interact with Slack workspaces as a user.

Tools

1. `slack_list_channels`

2. `slack_post_message`

3. `slack_reply_to_thread`

4. `slack_add_reaction`

5. `slack_get_channel_history`

6. `slack_get_thread_replies`

7. `slack_get_users`

8. `slack_get_user_profile`

Setup

1. Create a Slack App:

2. Configure User Token Scopes:

Navigate to "OAuth & Permissions" and add these scopes:

3. Install App to Workspace:

4. For organization-level tokens, get your Team ID (starts with a `T`) by following this guidance. It is optional for ordinary workspace tokens.

Treat OAuth tokens as secrets. Do not commit them, put them in issues or pull requests, or paste them into shared configuration. Rotate a token immediately if it is exposed.

Usage with Claude Desktop

Add the following to your `claude_desktop_config.json`:

Local Installation

First install and build the server:

git clone https://github.com/lars-hagen/slack-user-mcp.git
cd slack-user-mcp
npm install
npm run build

Then configure Claude Desktop:

{
  "mcpServers": {
    "slack": {
      "command": "npm",
      "args": [
        "run",
        "--prefix",
        "/path/to/slack-user-mcp",
        "start"
      ],
      "env": {
        "SLACK_TOKEN": "xoxp-your-user-token"
      }
    }
  }
}

NPX

This project is not published to npm. Do not use an `npx` package name for it. Clone and build it locally as shown above, then use the local configuration.

Docker

{
  "mcpServers": {
    "slack": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "SLACK_TOKEN",
        "slack-user-mcp"
      ],
      "env": {
        "SLACK_TOKEN": "xoxp-your-user-token"
      }
    }
  }
}

Build the image first with `docker build -t slack-user-mcp .`. Add `-e SLACK_TEAM_ID` and `SLACK_TEAM_ID` to `env` only when using an organization-level token.

Installing via Smithery

To install Slack User Server for Claude Desktop automatically via Smithery:

npx -y @smithery/cli install @lars-hagen/slack-user-mcp --client claude

Troubleshooting

If you encounter permission errors, verify that:

1. All required scopes are added to your Slack app

2. The app is properly installed to your workspace

3. The token and, when needed, workspace ID are correctly copied to your configuration

4. The app has been added to the channels it needs to access

5. You're using a User OAuth Token (starts with `xoxp-`) rather than a Bot Token

Build

Docker build:

docker build -t slack-user-mcp .

Maintenance status

This project receives focused, best-effort maintenance. It has no support SLA. Please report security concerns privately as described in SECURITY.md.

License

This MCP server is licensed under the MIT License. This means you are free to use, modify, and distribute the software, subject to the terms and conditions of the MIT License. For more details, please see the LICENSE file in the project repository.